The invention relates to the field of mounting electronic components or modules, in particular electrooptical modules (so-called transceivers). In order to provide for the mounting of such modules on carriers, in particular printed circuit boards provided with conductor tracks and terminal contacts, a user increasingly requires modules which can be placed on the printed circuit board, and made contact with, in a comparatively free and unrestricted manner. There is a requirement, in particular, for module structures and suitable connecting systems which allow the modules to be inserted horizontally, in a straightforward manner, into suitable mounts which, in addition to making electrical contact with the module, also ensure sufficiently tension-resistant mechanical fixing.
U.S. Pat. No. 5,734,558 discloses an optoelectronic component with an associated mount which is disposed on a top surface of a printed circuit board. The component and the mount are provided with interacting fixing devices. In that case, the component housing has resilient latching arms on both narrow sides which are free with respect to the optical terminal side. The latching arms are provided on the outside with latching tabs which latch into corresponding recesses of the mount when the component is introduced into an end position (connecting position) parallel to the surface of the carrier. In that position, the component is connected mechanically to the mount, in which case, at the same time, a male connector strip, that is disposed on that side of the component which is located opposite the optical terminal side, is given an electrical connection with a female connector strip of the mount.
Free ends of the latching arms have to be moved manually towards one another until the latching tabs are released from the recesses of the mount, for mounting and for removal. The known component requires a considerable amount of lateral access space to provide for the mounting and removal. Since a sufficient material cross section also has to be provided over the height of the narrow side for the latching arms, and a sufficient height of the operating surfaces (end regions of the latching arms) is necessary, the overall height of the component cannot be reduced below dimensions which are sufficient in this respect.
It is accordingly an object of the invention to provide a detachable connecting system, which overcomes the hereinaforementioned disadvantages of the heretofore-known devices of this general type, which has an extremely low overall height while being very user-friendly and which does not prevent a reduction in component height.
With the foregoing and other objects in view there is provided, in accordance with the invention, a detachable connecting system having a component and a mount which is disposed on a top surface of a carrier. The component and the mount are equipped with interacting guides which, when the connection is formed, bring about a guided movement of the component, in the mounting direction, relative to the mount, and parallel to the top surface of the carrier, into a connecting position. The component has a locking element on its underside, which is directed towards the carrier. The mount has a resilient tongue which extends, counter to the mounting direction, beneath the component, and has a locking partner at a free end of the tongue. The locking partner latches with the locking element of the component in the connecting position. An actuating region of the free end of the tongue is accessible from an end surface of the component in the connecting position.
A major advantage of the invention is a locking mechanism which acts resiliently on the component from beneath and has an extremely low overall height, of much less than 1.2 mm. The locking partner can nevertheless absorb considerable tensile loading in the horizontal direction. This, for example, provides a reliable mechanical fixing and connecting system for electrooptical modules, onto one end of which optical-conductor connectors can be plugged for optical coupling. It is possible for the optical-conductor connectors to be subjected to considerable tensile loading (of typically 40 to 60 N). A further major advantage of the invention is the accessibility of the actuating region from the component end surface, which is preferably formed as an optical coupling surface. As a result, it is possible for the component and the mount to be disposed directly alongside adjacent component parts without it being necessary to provide lateral access spaces alongside the component for mounting and removal. A further advantage is that the resilient tongue, which is disposed beneath the component, may have a width which is sufficient for actuation without rendering the component height subject to the restrictions outlined in the introduction.
In accordance with another feature of the invention, the resilient tongue is formed of metal and has mounting surfaces with which contact is made on the top surface of the carrier. A major advantage of the conductive tongue, which is, in particular, in the form of a single-piece metal punched part, is that, with extremely small component cross sections, the connection can nevertheless absorb very high tensile loading. Moreover, in the event of actuation overloading, the metal tongue is very robust and tends more to deformation (reversibly) than to fracturing. With excessive tensile forces, the locking element of the component would tend to flex but, in contrast, the mount, which is mounted on the printed circuit board and is difficult to replace, would remain intact. A further considerable advantage is that the conductive tongue may serve for electrical component shielding in that, in the locked state, it is connected electrically to corresponding shielding plates of the component and, for its part, is connected to shielding potential.
In accordance with a further feature of the invention, for this purpose, contact is also made with the tongue on the top surface of the carrier through its mounting surfaces.
In accordance with an added feature of the invention, which is preferred from a production point of view, another end of the tongue is accommodated by a retaining block of the mount. The retaining block also has at least parts of the guides of the mount.
In accordance with an additional feature of the invention, which is a particularly user-friendly configuration, the actuating region of the free end of the tongue is bent down in the direction of the top surface of the carrier and, in the connecting position, projects beyond the component end surface.
In accordance with a concomitant feature of the invention, which is particularly preferred in terms of both mounting and, in particular, removal, the component is moved into the connected end position counter to spring preloading. It is preferably possible in this case for the spring preloading to be produced by a spring disposed on the mount. This is particularly favorable from the point of view of production and mounting and, as far as the component-housing shape is concerned, allows a wide range of variants. The spring preloading is preferably selected in this case in such a way that, when the component is introduced into the mount, it becomes noticeable only over the last part of the fitting distance. For this purpose, it is possible to place a compression spring at the far end of the mount, as seen in the mounting direction. The compression spring comes into contact with the component or with an end surface of the component housing, just before the end position is reached. This means that the user can easily and conveniently be made aware that the component is just about to reach the end position. The spring preloading has considerable advantages, in particular for removal of the component. That is because, once the interacting locking partners have been unlocked, the component is ejected at least part way counter to the mounting direction, with the spring being relieved of stressing. As a result, on one hand, the component is reliably unlocked and, on the other hand, the component can be gripped more easily.
Other features which are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in a detachable connecting system, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.